On 26 Feb 2025, at 10:43, Adrian Moreno wrote:
> Generate events for dropped upcalls and add the print the result.
>
> Signed-off-by: Adrian Moreno <amore...@redhat.com>
One warning came from this patch:
utilities/usdt-scripts/upcall_monitor.py:29:80: E501 line too long (80 > 79
characters)
Other than this I see no problem. So with this fixed:
Acked-by: Eelco Chaudron <echau...@redhat.com>
> ---
> utilities/usdt-scripts/upcall_monitor.py | 135 +++++++++++++++++++----
> 1 file changed, 111 insertions(+), 24 deletions(-)
>
> diff --git a/utilities/usdt-scripts/upcall_monitor.py
> b/utilities/usdt-scripts/upcall_monitor.py
> index 3a758b2d2..4047c0085 100755
> --- a/utilities/usdt-scripts/upcall_monitor.py
> +++ b/utilities/usdt-scripts/upcall_monitor.py
> @@ -25,6 +25,8 @@
> # 5952147.003879643 2 handler4 1381158 system@ovs-system 0 70
> 160
> # 5952147.003914924 2 handler4 1381158 system@ovs-system 0 98
> 152
> #
> +# Also, upcalls dropped by the kernel (e.g: because the netlink buffer is
> full)
> +# are reported. This requires the kernel version to be greater or equal to
> 5.14.
> # In addition, the packet and flow key data can be dumped. This can be done
> # using the --packet-decode and --flow-key decode options (see below).
> #
> @@ -125,12 +127,13 @@ import sys
> # Actual eBPF source code
> #
> ebpf_source = """
> -#include <linux/sched.h>
> +#include <linux/skbuff.h>
>
> #define MAX_PACKET <MAX_PACKET_VAL>
> #define MAX_KEY <MAX_KEY_VAL>
>
> struct event_t {
> + int result;
> u32 cpu;
> u32 pid;
> u32 upcall_type;
> @@ -145,23 +148,28 @@ struct event_t {
> BPF_RINGBUF_OUTPUT(events, <BUFFER_PAGE_CNT>);
> BPF_TABLE("percpu_array", uint32_t, uint64_t, dropcnt, 1);
>
> +static
> +void report_missed_event() {
> + uint32_t type = 0;
> + uint64_t *value = dropcnt.lookup(&type);
> + if (value)
> + __sync_fetch_and_add(value, 1);
> +}
> +
> int do_trace(struct pt_regs *ctx) {
> uint64_t addr;
> uint64_t size;
>
> struct event_t *event = events.ringbuf_reserve(sizeof(struct event_t));
> if (!event) {
> - uint32_t type = 0;
> - uint64_t *value = dropcnt.lookup(&type);
> - if (value)
> - __sync_fetch_and_add(value, 1);
> -
> + report_missed_event();
> return 1;
> }
>
> event->ts = bpf_ktime_get_ns();
> event->cpu = bpf_get_smp_processor_id();
> event->pid = bpf_get_current_pid_tgid();
> + event->result = 0;
> bpf_get_current_comm(&event->comm, sizeof(event->comm));
>
> bpf_usdt_readarg(1, ctx, &addr);
> @@ -189,32 +197,87 @@ int do_trace(struct pt_regs *ctx) {
> events.ringbuf_submit(event, 0);
> return 0;
> };
> +
> +struct inflight_upcall {
> + u32 cpu;
> + u32 upcall_type;
> + u64 ts;
> + struct sk_buff *skb;
> + char dpif_name[32];
> +};
> +BPF_HASH(inflight_upcalls, u64, struct inflight_upcall);
> +
> +TRACEPOINT_PROBE(openvswitch, ovs_dp_upcall)
> +{
> + u64 pid = bpf_get_current_pid_tgid();
> + struct inflight_upcall upcall = {};
> +
> + upcall.cpu = bpf_get_smp_processor_id();
> + upcall.ts = bpf_ktime_get_ns();
> + upcall.upcall_type = args->upcall_cmd;
> + upcall.skb = args->skbaddr;
> + TP_DATA_LOC_READ_CONST(&upcall.dpif_name, dp_name,
> + sizeof(upcall.dpif_name));
> +
> + inflight_upcalls.insert(&pid, &upcall);
> + return 0;
> +}
> +
> +int kretprobe__ovs_dp_upcall(struct pt_regs *ctx)
> +{
> + u64 pid = bpf_get_current_pid_tgid();
> + struct inflight_upcall *upcall;
> + int ret = PT_REGS_RC(ctx);
> + u64 size;
> +
> + upcall = inflight_upcalls.lookup(&pid);
> + inflight_upcalls.delete(&pid);
> + if (!upcall)
> + return 0;
> +
> + /* Successfull upcalls are reported in the USDT probe. */
> + if (!ret)
> + return 0;
> +
> + struct event_t *event = events.ringbuf_reserve(sizeof(struct event_t));
> + if (!event) {
> + report_missed_event();
> + return 1;
> + }
> +
> + event->ts = upcall->ts;
> + event->cpu = upcall->cpu;
> + event->pid = pid;
> + event->result = ret;
> + __builtin_memcpy(&event->dpif_name, &upcall->dpif_name, 32);
> + bpf_get_current_comm(&event->comm, sizeof(event->comm));
> + event->pkt_size = upcall->skb->len;
> + event->upcall_type = upcall->upcall_type;
> + event->key_size = 0;
> +
> + size = upcall->skb->len - upcall->skb->data_len;
> + if (size > MAX_PACKET)
> + size = MAX_PACKET;
> +
> + bpf_probe_read_kernel(event->pkt, size, upcall->skb->data);
> + events.ringbuf_submit(event, 0);
> + return 0;
> +}
> """
>
>
> #
> -# print_event()
> +# print_key()
> #
> -def print_event(ctx, data, size):
> - event = b['events'].event(data)
> - print("{:<18.9f} {:<4} {:<16} {:<10} {:<32} {:<4} {:<10} {:<10}".
> - format(event.ts / 1000000000,
> - event.cpu,
> - event.comm.decode("utf-8"),
> - event.pid,
> - event.dpif_name.decode("utf-8"),
> - event.upcall_type,
> - event.pkt_size,
> - event.key_size))
> -
> - #
> - # Dump flow key information
> - #
> +def print_key(event):
> if event.key_size < options.flow_key_size:
> key_len = event.key_size
> else:
> key_len = options.flow_key_size
>
> + if not key_len:
> + return
> +
> if options.flow_key_decode != 'none':
> print(" Flow key size {} bytes, size captured {} bytes.".
> format(event.key_size, key_len))
> @@ -237,6 +300,30 @@ def print_event(ctx, data, size):
> else:
> port = "Unknown"
>
> + return port
> +
> +
> +#
> +# print_event()
> +#
> +def print_event(ctx, data, size):
> + event = b['events'].event(data)
> + print("{:<18.9f} {:<4} {:<16} {:<10} {:<32} {:<4} {:<10} {:<12} {:<8}".
> + format(event.ts / 1000000000,
> + event.cpu,
> + event.comm.decode("utf-8"),
> + event.pid,
> + event.dpif_name.decode("utf-8"),
> + event.upcall_type,
> + event.pkt_size,
> + event.key_size,
> + event.result))
> +
> + #
> + # Dump flow key information
> + #
> + port = print_key(event)
> +
> #
> # Decode packet only if there is data
> #
> @@ -501,9 +588,9 @@ def main():
> #
> # Print header
> #
> - print("{:<18} {:<4} {:<16} {:<10} {:<32} {:<4} {:<10} {:<10}".format(
> + print("{:<18} {:<4} {:<16} {:<10} {:<32} {:<4} {:<10} {:<12}
> {:<8}".format(
> "TIME", "CPU", "COMM", "PID", "DPIF_NAME", "TYPE", "PKT_LEN",
> - "FLOW_KEY_LEN"))
> + "FLOW_KEY_LEN", "RESULT"))
>
> #
> # Dump out all events
> --
> 2.48.1
>
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> dev mailing list
> d...@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
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